CVE-2021-34523

CRITICAL KEV RANSOMWARE

Microsoft Exchange Server - Privilege Escalation

Title source: llm

Description

Microsoft Exchange Server Elevation of Privilege Vulnerability

Exploits (9)

nomisec SCANNER 16 stars
by mithridates1313 · infoleak
https://github.com/mithridates1313/ProxyShell_POC
nomisec SCANNER 2 stars
by SUPRAAA-1337 · infoleak
https://github.com/SUPRAAA-1337/CVE-2021-34523
metasploit WORKING POC EXCELLENT
by Orange Tsai, Jang (@testanull), PeterJson, brandonshi123, mekhalleh (RAMELLA Sébastien), Donny Maasland, Rich Warren, Spencer McIntyre, wvu · rubypocwindows
https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/windows/http/exchange_proxyshell_rce.rb
patchapalooza WORKING POC
by horizon3ai · remote
https://github.com/horizon3ai/proxyshell
patchapalooza WORKING POC
by aravazhimdr · remote
https://github.com/aravazhimdr/ProxyShell-POC-Mod
patchapalooza WORKING POC
by Udyz · remote
https://github.com/Udyz/proxyshell-auto
patchapalooza WORKING POC
by dmaasland · remote
https://github.com/dmaasland/proxyshell-poc
patchapalooza WORKING POC
by ktecv2000 · remote
https://github.com/ktecv2000/ProxyShell
patchapalooza SCANNER
by cyberheartmi9 · remote
https://github.com/cyberheartmi9/Proxyshell-Scanner

Scores

CVSS v3 9.0
EPSS 0.9409
EPSS Percentile 99.9%
Attack Vector LOCAL
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N

Details

CISA KEV 2021-11-03
VulnCheck KEV 2021-08-30
InTheWild.io 2021-08-24
ENISA EUVD EUVD-2021-21177
Ransomware Use Confirmed
Status published
Products (3)
microsoft/exchange_server 2013 cumulative_update_23
microsoft/exchange_server 2016 cumulative_update_19 (2 CPE variants)
microsoft/exchange_server 2019 cumulative_update_8 (2 CPE variants)
Published Jul 14, 2021
KEV Added Nov 03, 2021
Tracked Since Feb 18, 2026